drm/i915/guc: Split guc_wq_item_append

We're using a special preempt context for HW to preempt into. We don't
want to emit any requests there, but we still need to wrap this context
into a valid GuC work item.
Let's cleanup the functions operating on GuC work items.
We can extract guc_request_add - responsible for adding GuC work item and
ringing the doorbell, and guc_wq_item_append - used by the function
above, not tied to the concept of gem request.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jeff McGee <jeff.mcgee@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171025200020.16636-7-michal.winiarski@intel.com

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index b0f034f924319d7a33bfb2be08299fede9d853f6..301c658a4cdea00dac9c63a39acaddbacdf70166 100644 (file)
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -71,7 +71,7 @@
  * WQ_TYPE_INORDER is needed to support legacy submission via GuC, which
  * represents in-order queue. The kernel driver packs ring tail pointer and an
  * ELSP context descriptor dword into Work Item.
- * See guc_wq_item_append()
+ * See guc_add_request()
  *
  * ADS:
  * The Additional Data Struct (ADS) has pointers for different buffers used by
@@ -394,7 +394,7 @@ static void guc_stage_desc_init(struct intel_guc *guc,
                 * submission or, in other words, not using a direct submission
                 * model) the KMD's LRCA is not used for any work submission.
                 * Instead, the GuC uses the LRCA of the user mode context (see
-                * guc_wq_item_append below).
+                * guc_add_request below).
                 */
                lrc->context_desc = lower_32_bits(ce->lrc_desc);
 
@@ -473,22 +473,18 @@ static void guc_shared_data_destroy(struct intel_guc *guc)
 
 /* Construct a Work Item and append it to the GuC's Work Queue */
 static void guc_wq_item_append(struct i915_guc_client *client,
-                              struct drm_i915_gem_request *rq)
+                              u32 target_engine, u32 context_desc,
+                              u32 ring_tail, u32 fence_id)
 {
        /* wqi_len is in DWords, and does not include the one-word header */
        const size_t wqi_size = sizeof(struct guc_wq_item);
        const u32 wqi_len = wqi_size / sizeof(u32) - 1;
-       struct intel_engine_cs *engine = rq->engine;
-       struct i915_gem_context *ctx = rq->ctx;
        struct guc_process_desc *desc = __get_process_desc(client);
        struct guc_wq_item *wqi;
-       u32 ring_tail, wq_off;
+       u32 wq_off;
 
        lockdep_assert_held(&client->wq_lock);
 
-       ring_tail = intel_ring_set_tail(rq->ring, rq->tail) / sizeof(u64);
-       GEM_BUG_ON(ring_tail > WQ_RING_TAIL_MAX);
-
        /* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we
         * should not have the case where structure wqi is across page, neither
         * wrapped to the beginning. This simplifies the implementation below.
@@ -510,15 +506,14 @@ static void guc_wq_item_append(struct i915_guc_client *client,
        /* Now fill in the 4-word work queue item */
        wqi->header = WQ_TYPE_INORDER |
                      (wqi_len << WQ_LEN_SHIFT) |
-                     (engine->guc_id << WQ_TARGET_SHIFT) |
+                     (target_engine << WQ_TARGET_SHIFT) |
                      WQ_NO_WCFLUSH_WAIT;
-
-       wqi->context_desc = lower_32_bits(intel_lr_context_descriptor(ctx, engine));
-
+       wqi->context_desc = context_desc;
        wqi->submit_element_info = ring_tail << WQ_RING_TAIL_SHIFT;
-       wqi->fence_id = rq->global_seqno;
+       GEM_BUG_ON(ring_tail > WQ_RING_TAIL_MAX);
+       wqi->fence_id = fence_id;
 
-       /* Postincrement WQ tail for next time. */
+       /* Make the update visible to GuC */
        WRITE_ONCE(desc->tail, (wq_off + wqi_size) & (GUC_WQ_SIZE - 1));
 }
 
@@ -551,6 +546,25 @@ static void guc_ring_doorbell(struct i915_guc_client *client)
        GEM_BUG_ON(db->db_status != GUC_DOORBELL_ENABLED);
 }
 
+static void guc_add_request(struct intel_guc *guc,
+                           struct drm_i915_gem_request *rq)
+{
+       struct i915_guc_client *client = guc->execbuf_client;
+       struct intel_engine_cs *engine = rq->engine;
+       u32 ctx_desc = lower_32_bits(intel_lr_context_descriptor(rq->ctx, engine));
+       u32 ring_tail = intel_ring_set_tail(rq->ring, rq->tail) / sizeof(u64);
+
+       spin_lock(&client->wq_lock);
+
+       guc_wq_item_append(client, engine->guc_id, ctx_desc,
+                          ring_tail, rq->global_seqno);
+       guc_ring_doorbell(client);
+
+       client->submissions[engine->id] += 1;
+
+       spin_unlock(&client->wq_lock);
+}
+
 /**
  * i915_guc_submit() - Submit commands through GuC
  * @engine: engine associated with the commands
@@ -562,10 +576,8 @@ static void i915_guc_submit(struct intel_engine_cs *engine)
 {
        struct drm_i915_private *dev_priv = engine->i915;
        struct intel_guc *guc = &dev_priv->guc;
-       struct i915_guc_client *client = guc->execbuf_client;
        struct intel_engine_execlists * const execlists = &engine->execlists;
        struct execlist_port *port = execlists->port;
-       const unsigned int engine_id = engine->id;
        unsigned int n;
 
        for (n = 0; n < execlists_num_ports(execlists); n++) {
@@ -579,14 +591,7 @@ static void i915_guc_submit(struct intel_engine_cs *engine)
                        if (i915_vma_is_map_and_fenceable(rq->ring->vma))
                                POSTING_READ_FW(GUC_STATUS);
 
-                       spin_lock(&client->wq_lock);
-
-                       guc_wq_item_append(client, rq);
-                       guc_ring_doorbell(client);
-
-                       client->submissions[engine_id] += 1;
-
-                       spin_unlock(&client->wq_lock);
+                       guc_add_request(guc, rq);
                }
        }
 }